SANDWICH TERN. 543 



rapid, making a great advance at each stroke of tlie pinions, 

 and, except when engaged in incubation, it is almost con- 

 stantly on the wing, uttering at intervals a hoarse and grating 

 cry, hirli'dt, kirhUt, which can be heard at a great distance. 



The adult bird in summer has the bill black, the tip 

 lemon-yellow ; the irides hazel ; all the parts of the head 

 above the eyes black ; the feathers on the occiput elongated, 

 forming a loose plume which ends in a point ; cheeks, sides, 

 and lower part of the neck behind, white ; back and wings, 

 pearl-grey, the ends of the secondaries and upper primaries, 

 almost white ; the longest primary slate-grey, with a white 

 shaft, the next three primaries diminishing in colour in 

 succession till they become of the same tint as the wing- 

 coverts ; tips and inner margins of webs, white ; the tail white 

 and forked ; chin, throat, neck in front, breast, and all the 

 under surface of the body white, often suffused with a lovely 

 salmon-pink ; legs, toes, and their membranes black, claws 

 curved and black. The whole length of the bird, from the 

 point of the beak to the end of the longest tail-feather, is 

 fifteen inches. From the carpal joint to the end of the 

 longest quill-feather twelve inches. In winter the forehead 

 and crown are white, spotted and streaked with black. 



A young bird of the year killed on the 10th of August 

 is about ten inches in length ; the upper mandible dark 

 brown, the under one pale brown at the base ; forehead 

 greyish- white, top of the head and the occiput black ; back 

 and smaller wing-coverts ash-grey, varied with pale brown ; 

 greater coverts ash-grey, quill-feathers bluish-grey, the inner 

 margins white, the outside quill-feather almost black, except 

 the shaft, which is white ; tail-feathers varied with ash-grey 

 and brown ; legs, toes, and membranes dark brown. 



The young bird figured in the illustration has the head 

 mottled Avith black and white ; the back, wing-coverts and 

 tail-feathers varied with angular lines of black. 



A nestling about three days old, taken on Norderney, has 

 the upper parts finely mottled with buff'y-grey ; under parts 

 white ; bill yellowish ; legs and feet greyish-brown ; webs 

 paler. 



